1. Field of the Invention
This invention relates to well servicing equipment, and more particularly, to apparatus for conducting pressurized fluids from a service vehicle to a wellhead.
2. Description of the Prior Art
During the course of producing fluids from a petroleum well it is often desirable or necessary to subject the well to a treatment procedure in order to stimulate its fluid production. This procedure usually involves the injection of fluids under high pressure, such as 20,000 psi, to fracture the producing earth formations, or the injection of an acid solution to dissolve or otherwise remove flow obstructing material, thereby increasing the flow of petroleum from the formation into the well. In order to carry out these well stimulation procedures, it is commonplace to employ an articulated pipe assembly, called a service line, to conduct the fluid from a pump system to the wellhead. Such a service line usually comprises a plurality of straight links of rigid pipe interconnected end-to-end by pipe swivel joints, and sufficient pipe unions to facilitate disassembly into sections that can be handled manually.
Where pipe of larger than normal diameter and thus of greater weight is used, in order to increase the volume of fluid injected into the well at a given time period, or to reduce the time for injecting a given fluid volume, additional personnel and/or time are required to unload the service line sections from their transport, assemble them and connect the line to the wellhead and then disassemble the line and reload the sections upon completion of fluid injection. Another disadvantage of a conventional service line is that it rests unrestrained on the ground between the transport and the wellhead and thus is free to whip about and possibly injure personnel or equipment if it breaks under pressure. Fluid flowing through the service line causes the line to vibrate so that the line may sink into any ground that is muddy or soft.
It is also known to employ an articulated well service pipeline mounted on a mobile telescoping boom assembly. This articulated pipeline may include a relatively large number of fairly short sections of pipe interconnected by a plurality of elbows and swivel joints that extend from and retract into their rest or stowed position in an accordion-like manner. Such accordion-type service lines are moved from a folded position toward an extended position by first unfolding the outboard portion of the service line and then successively unfolding other portions nearest the unfolded outboard portion as the outboard end of the line is moved outward. This causes the individual pipe sections to be oriented in a generally vertical position with the lower end of each pipe section adjacent the service vehicle where such pipe sections may collide with obstacles which may be on the service vehicle.